Cosmetic compositions

ABSTRACT

An improved process for the preparation of cosmetic formulations containing a cosmetic active and a continuous phase comprising a water-immiscible liquid carrier, that are structured by a cyclo dipeptide (CDP) having the general formula  
                 
 
     in which R 1  and/or R 2 , which may be the same or preferably different, each represents a hydrocarbon or alkylene ester group and the other may alternatively represent hydrogen, which employs a monohydric alcohol having a melting point of below  30 ° C. and a boiling point of greater than  100 ° C. and a cosmetic active material optionally together with at least one water-immiscible liquid carrier oil to assist in the dissolution of the structurant and modify the gelling temperature of the resultant mixture. Preferably, the CDP is dissolved in the monohydric alcohol and optionally up to half the water-immiscible oil prior to being mixed with the remaining ingredients of the composition.

FIELD OF THE INVENTION

[0001] The present invention relates to cosmetic compositions forapplication to human skin, to the preparation and use of suchcompositions and to structurants for incorporation in such compositionsand their preparation.

BACKGROUND OF THE INVENTION AND SUMMARY OF PRIOR ART

[0002] A wide variety of cosmetic compositions for application to humanskin make use of a structured liquid carrier to deliver colour or someother active material to the surface of the skin. Significant examplesof such cosmetic compositions include antiperspirant or deodorantcompositions which are widely used in order to enable their users toavoid or minimise wet patches on their skin, especially in axillaryregions or to control or prevent the emission of malodours, which couldotherwise arise when the user perspires. Other examples of cosmeticcompositions include lip sticks.

[0003] Although structuring is a term that has often been employed inrespect of materials which structure a carrier liquid, various otherterms have been employed alternatively, including thickening,solidifying and gelling.

[0004] Antiperspirant or deodorant formulations have been provided witha range of different product forms. One of these is a so-called “stick”which is usually a bar of an apparently firm solid material held withina dispensing container and which retains its structural integrity andshape whilst being applied. In that respect they are representative ofcosmetic compositions in stick form containing other activeconstituents. When a portion of the stick is drawn across the skinsurface, a film of the stick composition is transferred to the skinsurface. Although the stick has the appearance of a solid articlecapable of retaining its own shape for a period of time, the materialoften has a structured liquid phase so that a film of the composition isreadily transferred from the stick to another surface upon contact.

[0005] Antiperspirant sticks can be divided into three categories.Suspension sticks contain a particulate antiperspirant active materialsuspended in a structured carrier liquid phase which often is anhydrousand/or in many instances may be water-immiscible. Emulsion sticksnormally have a hydrophilic phase, commonly containing theantiperspirant active in solution, this phase forming an emulsion with asecond, more hydrophobic, liquid phase. The continuous phase of theemulsion is structured. Solution sticks typically have theantiperspirant active dissolved in a structured liquid phase which ispolar and may comprise a polar organic solvent, which is oftenwater-miscible, and the polar phase can contain water.

[0006] There is substantial literature on structuring of cosmeticcompositions, for example as represented by antiperspirant or deodorantcompositions.

[0007] Conventionally, many sticks have been structured usingnaturally-occurring or synthetic waxy materials, in which term weinclude materials which resemble beeswax, in that they softenprogressively with increase in temperature until they are fluid,generally by about 95° C. Examples of wax-structured sticks aredescribed in an article in Cosmetics and Toiletries, 1990, Vol 105,P75-78, in U.S. Pat. Nos. 5,169,626 and 4,725,432 and in many otherpublications, in some of which such materials are called solidifyingagents.

[0008] More specifically, it has been common practice for sticks to bestructured or solidified by incorporating fatty alcohol into thecomposition, often accompanied by a smaller amount of castor wax. Stickswhich are structured with fatty alcohol tend to leave visible whitedeposits on application to human skin; moreover the deposits can alsotransfer onto clothing when it comes into contact with the skin and thewearer can, for example, find white marks at the armhole of thesleeveless garment. Fatty alcohols are often regarded as coming withinthe general category of waxy materials, but we have observed that theyare a more significant source of white deposits than various other waxymaterials.

[0009] Some alternative structurants or solidifying agents to waxymaterials have been proposed. For example, the use of dibenzylidenesorbitol (DBS) or derivatives thereof as gellant for a polar orhydrophylic carrier liquid has been proposed in a number of publicationssuch as EP-A-512770, WO-92/19222, U.S. Pat. Nos. 4,954,333, 4,822,602and 4,725,430. Cosmetic formulations containing such gellants can sufferfrom a number of disadvantages, including instability in the presence ofacidic antiperspirants, and comparatively high processing temperaturesneeded in the production of sticks.

[0010] Other alternative proposed structurants include various classesof esters or amides that are solid at ambient temperature and arecapable of solidifying a hydrophobic or water-immiscible liquid carrier.One such class comprises ester or amide derivatives of 12-hydroxystearicacid, as described in inter alia U.S. Pat. No. 5,750,096. Another classof such esters or amides comprises N-acyl amino acid amides and esters,of which N-Lauroyl-L-glutamic acid di-n-butylamide is commerciallyavailable from Ajinomoto under their designation GP-1. They aredescribed in U.S. Pat. No. 3,969,087. A further class which has beendisclosed as gelling agents comprises the amide derivatives of di andtribasic carboxylic acids set forth in WO 98/27954 notably alkylN,N′-dialkyl succinamides. Yet other amide structurants forwater-immiscible liquid carriers are described in EP-A-1305604.

[0011] One further class of compounds that have been contemplated as agelator for cosmetic oils comprises cyclodipeptides. Such compoundscontain a —CO—NH— group, and can be considered to be cyclic derivativesof aminoacids.

[0012] Various cyclodipeptides has been described in an article by KHanabusa et al entitled Cyclo(dipeptide)s as low molecular-mass GellingAgents to harden Organic Fluids, J. Chem Soc. Commun., 1994 pp1401/2.Various other cyclo(dipeptides) satisfying formula 1 above weredescribed in a second article by Hanabusa et al entitled Low Molecular

[0013] Weight Gelators for Organic Fluids: Gelation using a Family ofCyclo(dipeptide)s, in the Journal of Colloid and Interface Science 224,231-244 (2000). Further cyclodipeptides have been described in JapaneseKokai 10-226615 (1998) or 13-247451 (2001) to Polar Chemical IndustriesInc. in which Hanabusa was a named inventor. In the course of theresearch leading to the present invention, cyclo-dipeptides such asvarious of those disclosed by Hanabusa were investigated and a sub-classof cyclo dipeptides exhibiting superior gelating properties wasidentified and described in an as yet unpublished copending applicationno GB0201164.1 filed in GB on 18 Jan. 2002.

[0014] Without being bound to any specific theory or explanation, webelieve that, upon structuring of a water-immiscible oil, a network offibres is formed of the cyclodipeptides that extends throughout theliquid phase, at least increasing the viscosity of the phase andpreferably gelling that phase. Upon heating the gel to the gel meltingtemperature, the strands of structurant dissolve and the liquid phasebecomes more mobile. Within the class of compounds identified ascyclodipeptides, the capability of individual members of that class toform a network and the conditions in which a network forms will vary, aswill the stability of a network, once formed. However, the class sharesthe properties outlined below to a greater or lesser extent.

[0015] Although cyclo dipeptides can be extremely effective gellants forcosmetic oils, the manufacture of compositions in which they areemployed as gellants is subject to a number of practical constraints ordifficulties. First, it is often difficult to incorporate sufficientcyclic dipeptide into the cosmetic oil to enable it to structure or gelthe oil to the extent that would be preferred by the manufacturer. Thatis because the cyclic dipeptides are relatively poorly soluble incommonly employed cosmetic oils, such as volatile or even non-volatilesilicone oils. It would be inherently desirable to find a way ofincreasing the solubility of cyclo dipeptides in the water-immiscibleliquid phase of cosmetic formulations.

[0016] A further property of cyclic dipeptides relates to the gellingtemperature of cosmetic oils containing them. As a generalisation, theytend to gel at higher temperatures than for example waxes or likecommonly employed gellants. Furthermore, and unsurprisingly, the gellingtemperature of a solution of such a gellant in such oils increases asits concentration in solution increases. The net consequence of itsgelation behaviour is that if enough cyclic dipeptide is present tocause the resultant product to have a preferred firmness at ambienttemperature, the gelation temperature of the cyclic dipeptide in the oilis undesirably high, commonly in the region of or in excess of 100° C.At such temperatures, many cosmetic oils can evaporate or becomediscoloured and if the formulation is in the form of an emulsion stick,water evaporation renders the preparation of accurate compositionextremely difficult and at worst impossible. Moreover, increasedprocessing temperatures can also result in degradation or discolorationof some cyclic dipeptides themselves. It would be inherently desirableto find a way of lowering the gelling temperature at which awater-immiscible oil phase occurs to a controllable extent.

[0017] The instant inventors accordingly concluded that it would bedesirable to identify variations in processing that could ameliorate orovercome the foregoing operational constraints, preferably both at thesame time.

SUMMARY OF THE INVENTION

[0018] Applicants have now found that the processing of cosmeticformulations employing a cyclodipeptide as a gelling agent for acosmetic oil carrier can be improved by employing a class of materialsthat can act as a solvent for the cyclo dipeptides and which is misciblewith the cosmetic oils.

[0019] It is an object of the present invention to provide structuredcosmetic compositions, in which a liquid carrier material is structuredusing a cyclo dipeptide structurant in the presence of a solvent for thecyclo dipeptide which is miscible with the carrier.

[0020] Broadly, in a first aspect of the present invention, there isprovided a cosmetic composition comprising:

[0021] (i) a cosmetic active material

[0022] (ii) a continuous phase which comprises a monohydric alcoholhaving a melting point of below 30° C. and a boiling point of greaterthan 100° C. and optionally at least one water-immiscible liquid carrieroil

[0023] (ii) a structurant for the continuous phase which comprises acyclodipeptide having the general formula 1

[0024] in which at least one of R₁ and R₂ which may be the same ordifferent represents an aliphatic group that is optionally substitutedby an aromatic or cycloaliphatic group and the other may alternativelyrepresent hydrogen.

[0025] Such an monohydric alcohol is miscible with commonly employed orcontemplated water-immiscible cosmetic oils and therefore be employed toameliorate the problems identified above, whilst still retaining thebenefits from employing such oils.

[0026] By employing a monohydric alcohol having the physical attributesidentified above as an essential component of the continuous carrier forthe cosmetic active, it is possible to render it easier to obtainstructured compositions using the selected structurant, and can also oralternatively enable compositions to be obtained in which the problem ofundesirable discoloration can be reduced or eliminated. Theincorporation of the selected alcohol can lower the temperature at whichthe desired concentration of structurant dissolves when the carrier alsocomprises a water-immiscible oil and can also increase the concentrationof the cyclic dipeptide which can dissolve in the carrier phase, andfurthermore can ameliorate or avoid the problem of the mixture becomingimmobile at an excessively high temperature.

[0027] A solution of the structurant in the cyclo dipeptide compound inthe monohydric alcohol or its optional mixture with a water-immiscibleoil indicates herein that a separate distinct structurant phase is nolonger discernible to the human eye.

[0028] A composition of this invention will generally be marketed in acontainer by means of which it can be applied at time of use. Thiscontainer may be of conventional type.

[0029] A second aspect of the invention therefore provides a cosmeticproduct comprising a dispensing container having an aperture fordelivery of the contents of the container, means for urging the contentsof the container through the said aperture, and a composition of thefirst aspect of the invention in the container.

[0030] Means for urging the contents of the container to the saidaperture or apertures, for flow through them, may be moving partsoperable by the user or an orifice in the container opposite theaperture providing digital access.

[0031] According to a third aspect of the present invention there isprovided a process for the production of a cosmetic compositioncomprising the steps of:

[0032] a) forming a mixture containing a liquid carrier, a structurantdissolved therein, and a solid or a disperse liquid phase comprisingcosmetic active in particulate or dissolved form at a temperature of atleast 40° C. and is above the setting temperature of the mixture;

[0033] b) introducing the mixture into a mould which preferably is adispensing container, and

[0034] c) cooling or permitting the mixture to cool to ambienttemperature, characterised in that the structurant is a cyclo dipeptidethat satisfies the general formula 1:

[0035] in which at least one of R₁ and R₂ which may be the same ordifferent represents an aliphatic group that is optionally substitutedby an aromatic or cycloaliphatic group and the other may alternativelyrepresent hydrogen,

[0036] and the carrier comprises a monohydric alcohol having a meltingpoint of below 30° C. and a boiling point of greater than 100° C., acosmetic active material and optionally at least one water-immiscibleliquid carrier oil,

[0037] A suspended solid may be any cosmetic active that is at leastpartly insoluble in a lypophilic water-immiscible liquid carrier in theamount incorporated therein and a disperse liquid phase may be asolution of such an active in a hydrophilic or polar solvent.

[0038] The cyclo dipeptide may conveniently be dissolved in themonohydric alcohol alone or in the presence of only a fraction of anywater-immiscible cosmetic oil. Alternatively, all the cosmetic oil canbe present at the dissolution stage. The former process variant isparticularly desired.

[0039] In a fourth aspect of the present invention, the cosmetic activecomprises an antiperspirant or deodorant active. Thus, according to thefourth aspect, there is provided a cosmetic method for preventing orreducing perspiration or odour formation on human skin comprisingtopically applying to the skin a composition comprising a cosmeticactive, a water-immiscible liquid carrier and a structurant compound asdefined above in the first aspect in which the cosmetic active is anantiperspirant or deodorant active.

DETAILED DESCRIPTION AND EMBODIMENTS

[0040] The present invention relates to compositions containing acosmetic active and a water-immiscible phase that is structured with acyclodipeptide, to a process for their preparation, to their use and toproducts containing them. Such compositions and the dispensing packagewill be described in greater detail, including preferences forindividual constituents and combinations thereof and preferred processoperations.

[0041] Structurant—Cyclo Dipeptides

[0042] The cyclo dipeptides, sometimes referred to subsequently hereinas CDPs, that can be employed in the instant invention can comprise anycyclo dipeptide that satisfies general formula 1 above.

[0043] It will recognised that the extent to which a CDP is able tostructure a water-immiscible carrier liquid or mixture containing it andthe properties of the resultant structured material depend upon manyfactors, including the CDP itself, the chemical nature of thewater-immiscible oil or mixture containing it, and the weight ratio ofDPD to the oils. For example, different CDPs have different inherentcapabilities to structure oils, often manifesting itself in the range ofoils which they can structure and/or the long term physical stability ofthe resultant structured oil and different oils have different inherentpropensity to be structured, often manifesting itself in the range ofCDPs that can structure them. An increasing ratio of CDP to carrier oilassists in structuring the oil. Structuring herein indicates theformation of a composition having an increased viscosity compared with acorresponding composition free from CDP, but more desirably the CDP/oilsand proportions are chosen together such that the composition is gelledat ambient temperature. A gelled composition does not flow within 24hours out of a filled container of 2 cm diameter that is lainhorizontally at 20° C. It can be assessed more quickly as having gelledby employing the test iii) described hereinafter.

[0044] In the CDPs herein, R₁ and/or R₂ are desirably linked to thecyclodipeptide nucleus through a methylene group —CH₂—. Commonly, R₁ isdifferent from R₂. In many suitable embodiments, one of R₁ and R₂ (theother being H) or more preferably both R₁ and R₂ are selected fromaliphatic hydrocarbon groups, preferably saturated, which may be linearor branched, optionally terminating in or substituted by an aryl orcycloaliphatic group, and from aliphatic esters of formula—(CH₂)_(n)—CO₂—R₃ in which in which n is 0 or preferably an integer ofat least 1 and R₃ represents an alkyl, cycloalkyl or aryl group. Thenumber of carbons in each of R₁ and R₂ is often selected in the range offrom 1 to 35 and in many instances from 1 to 20.

[0045] Examples of suitable alkyl groups for R₁ and/or R₂ include ethyl,isopropyl, and isobutyl groups. Others which may be contemplated include2-ethylbutyl, hexyl, 3-methyl-isononyl, and dodecanyl. Examples ofsuitable aliphatic ester groups for R₁ and/or R₂ include esters in whichn=0 or 1 or 2, and particularly where n=1. In such or other estergroups, R₃ can represents an alkyl group containing at least 2 carbons,particularly up to 20 carbons, which may be linear or branched, such asan ethyl, isopropyl, isobutyl, 2-ethylbutyl, hexyl, 3-methyl-isononyl,dodecanyl, hexadecanyl or octadecanyl group.

[0046] In a number of preferred embodiments, R₃ represents a carbocyclicor heterocyclic group.

[0047] In such embodiments, R₃ can comprise two fused rings, butpreferably comprises a single six membered ring, either carbocyclic orheterocyclic, or a bridged ring. When R₃ is carbocyclic, it can beeither saturated or unsaturated, preferably mono- or di-unsaturated oraromatic. When R₃ is heterocyclic, it is preferably saturated.

[0048] R₃ is preferably substituted by at least one alkyl substituent,R₄, either directly onto the ring or optionally indirectly via aninterposed ether or ester linkage. R₄ preferably contains no more that19 carbon atoms, such as one having a longest chain length of up to 4carbon atoms, and/or a total carbon content of up to 5 carbon atoms. R₄may be linear or branched. Preferred examples include methyl, ethyl,propyl, isopropyl, butyl isobutyl or t-butyl or isopentyl. In a numberof very suitable cyclo dipeptides, at least two or more R₄ substituentsare present, both or all especially desirably being selected from theabove list of preferred examples. The R₄ substituents may be the same,such as two or more methyl substituents, or may be a combination ofdifferent substituents such as a methyl and isopropyl substituents. WhenR₃ is saturated, the R₄ substituents may depend from the same carbonatom in the ring, such as two methyl groups, or from different carbonatoms. In several highly desirable cyclic dipeptides, two alkyl R₄substituents are meta or para to each other, for example two methylgroups that are meta to each other or a methyl group and an isopropylgroup that are para to each other. In yet other cyclo dipeptides, thering may include a methylene bridge, which preferably likewise completesa six membered ring.

[0049] When R₄ is linked to the ring via an ester linkage, the carbonylcarbon in the ester linkage is preferably directly bonded to the ring.In various desirable cyclic dipeptides, R₃ satisfies the formula—Ph—CO—O—R₄ in which R₄ is as described above and particular where R₄comprises 3 to 6 carbons, such as n-butyl.

[0050] When R_(A) is heterocyclic, the heterocyclic atom is suitablynitrogen. Conveniently, the heterocyclic atom can be para to the bondwith the cyclo dipeptide residue. Moreover, in a number of desirablecyclo dipeptides, the heteroatom is ortho to at least one alkyl groupR₄, better in a saturated ring and especially to up to 4 ortho R₄groups, that especially are methyl groups.

[0051] Examples of such especially preferred R₃ group include thymol,isopinocamphenol and 3,5-dialkyl cyclohexanol such as 3,5-dimethylcyclohexanol.

[0052] In several highly desirable embodiments, R₁ represents a benzylgroup and R₂ is an ester of formula (CH₂)_(n)—CO₂—R₃ especially those inwhich n=1, and R₃ represent a carbocylic or heterocyclic group asdescribed above.

[0053] Continuous Phase—Carrier Oils

[0054] Herein, the carrier oils include a monohydric alkanol oiloptionally together with at least one water-immiscible carrier cosmeticoil.

[0055] The monohydric alkanol for employment in herein can comprise anyalkanol which has a melting point that is no higher than 30° C. and aboiling point that is greater than 100° C. Preferred alkanols have amelting point that is below 25° C. and especially below 20° C.Preferably, the alkanols have a boiling point that is greater than 120°C. and particularly one that is greater than 150° C. Boiling point andmelting point data for alkanols is commonly available, or can be readilydetermined using standard apparatus. Without being prescriptive,alkanols having a suitable melting point and boiling point can beselected from intermediate chain length linear alkanols, such as butanolthrough to decanol, eg octanol or decanol; or short cycloalkanols suchas cyclopentanol through to cycloheptanol, optionally methylsubstituted; intermediate or longer chain length branched alkanols,containing for example from 5 to 24 carbons and especially at least 10carbons, such as secondary aliphatic alcohols, eg isolauryl alcoholisocetyl alcohol isopalmityl alcohol and isostearyl alcohol or secondaryalcohols in which the branch contains from 2 to 10 carbons, such asoctyl dodecanol. Still other suitable alcohols can be selected fromphenyl-terminated short chain aliphatic alcohols, such a benzyl alcoholand phenylethyl alcohol. Mixtures of such alcohols can be employed, bothwithin the sub-classes of alcohols and between the sub-classes.

[0056] It is beneficial to choose monohydric alcohols that themselvesare comparatively water-immiscible or at best poorly miscible. Inpractice, the monohydric alcohols above-identified by name normallysatisfy such a preference and such a property is ascertainable fromstandard reference works. Any doubt can be resolved by conducting asimple test. In such a test, preferred alcohols are those which areincapable of forming a stable, single phase when mixed gently withde-ionised water (ie in the absence of any solubilising agent orhydrotrope) at 25° C. in a weight ratio of 20 parts alcohol to 80 partswater.

[0057] The continuous phase carrier liquid system commonly comprises oneor a mixture of materials which are relatively hydrophobic so as to beimmiscible in water, in addition to the monohydric alcohol.

[0058] The weight proportion of the monohydric alcohol in the carrierliquid is at the discretion of the user. Naturally, it will beunderstood that the beneficial lowering of the gelation temperatureand/or the increase in concentration of structurant that can beincorporated increases non-linearly with the proportion of themonohydric alcohol in the carrier. In practice, the choice of weightproportions takes into account many factors, such as the extent to whicha particular CDP suffers from the problems in water-immiscible oilsdescribed in the introductory section of this text, and/or which sensoryor physical properties are more preferred in the eventual product. Theproportion of the monohydric alcohol is normally selected in the rangeof from 5 to 100% of the weight of the carrier oils. In manyembodiments, its weight proportion is at least 20%. To permitsignificant variation in the sensory properties of the eventualcomposition, the weight proportion of the monohydric alcoholconveniently is not more than 70% or 80% of the carrier oils.

[0059] The more the monohydric alcohol that is present, the greater theextent to which it can enhance the solubility of the CDP and lower thegelling temperature of the liquid carrier. In many compositionsaccording to the present invention, the selected monohydric alcohol ispresent in a weight ratio to the CDP of at least 1:1, particularly atleast 2:1 and in many practical embodiments is at least 4:1. Although aweight ratio to the CDP of greater than 100:1 can be contemplated, theweight ratio is normally up to 100:1, and in many instances is up to70:1. In various practical embodiments, the weight ratio to CDP is up to20:1.

[0060] Some hydrophilic liquid may be included in the carrier, providedthe overall carrier liquid mixture is immiscible with water. It willgenerally be desired that this carrier is liquid (in the absence ofstructurant) at temperatures of 15° C. and above. It may have somevolatility but its vapour pressure will generally be less than 4 kPa (30mmHg) at 25° C. so that the material can be referred to as an oil ormixture of oils. More specifically, it is desirable that at least 80% byweight of the hydrophobic carrier liquid should consist of materialswith a vapour pressure not over this value of 4 kPa at 25° C.

[0061] It is preferred that the hydrophobic carrier material includes avolatile liquid silicone, i.e. liquid polyorganosiloxane. To class as“volatile” such material should have a measurable vapour pressure at 20or 25° C. Typically the vapour pressure of a volatile silicone lies in arange from 1 or 10 Pa to 2 kPa at 25° C.

[0062] It is desirable to include volatile silicone because it gives a“drier” feel to the applied film after the composition is applied toskin.

[0063] Volatile polyorganosiloxanes can be linear or cyclic or mixturesthereof. Preferred cyclic siloxanes include polydimethylsiloxanes andparticularly those containing from 3 to 9 silicon atoms and preferablynot more than 7 silicon atoms and most preferably from 4 to 6 siliconatoms, otherwise often referred to as cyclomethicones. Preferred linearsiloxanes include polydimethylsiloxanes containing from 3 to 9 siliconatoms. The volatile siloxanes normally by themselves exhibit viscositiesof below 10⁻⁵ m²/sec (10 centistokes), and particularly above 10⁻⁷m²/sec (0.1 centistokes), the linear siloxanes normally exhibiting aviscosity of below 5×10⁻⁶m²/sec (5 centistokes). The volatile siliconescan also comprise branched linear or cyclic siloxanes such as theaforementioned linear or cyclic siloxanes substituted by one or morependant —0—Si(CH₃)₃ groups. Examples of commercially available siliconeoils include oils having grade designations 344, 345, 244, 245 and 246from Dow Corning Corporation; Silicone 7207 and Silicone 7158 from UnionCarbide Corporation; and SF1202 from General Electric.

[0064] The hydrophobic carrier employed in compositions herein canalternatively or additionally comprise non-volatile silicone oils, whichinclude polyalkyl siloxanes, polyalkylaryl siloxanes andpolyethersiloxane copolymers. These can suitably be selected fromdimethicone and dimethicone copolyols. Commercially availablenon-volatile silicone oils include products available under thetrademarks Dow Corning 556 and Dow Corning 200 series. Other nonvolatile silicone oils include that bearing the trademark DC704.Incorporation of at least some non-volatile silicone oil having a highrefractive index such as of above 1.5, eg at least 10% by weight(preferably at least 25% to 100% and particularly from 40 to 80%) of thesilicone oils is often beneficial in some compositions, because thisrenders it easier to match the refractive index of the constituents ofthe composition and thereby easier to produce transparent or translucentformulations.

[0065] The water-immiscible oil employed in the carrier in addition tothe monohydric alcohol may comprise from 0% to 100% by weight of one ormore liquid silicones. In some embodiments, there is sufficient liquidsilicone to provide at least 10%, better at least 15%, by weight of thewhole composition. When silicone oil is used in various embodiments, forexample in emulsions, volatile silicone preferably constitutes from 20to 100% of the weight of the carrier liquid. In a number of embodiments,when a non-volatile silicone oil is present, its weight ratio tovolatile silicone oil is chosen in the range of from 5:1 to 1:50.

[0066] Silicon-free hydrophobic oils can be used instead of, or morepreferably in addition to liquid silicones. Silicon-free hydrophobicorganic oils that can be incorporated include liquid aliphatichydrocarbons such as mineral oils or hydrogenated polyisobutene, oftenselected to exhibit a low viscosity. Further examples of liquidhydrocarbons are polydecene and paraffins and isoparaffins of at least10 carbon atoms.

[0067] Other suitable hydrophobic carriers comprise liquid aliphatic oraromatic esters. Suitable aliphatic esters contain at least one longchain alkyl group, such as esters derived from C₁ to C₂₀ alkanolsesterified with a C₈ to C₂₂ alkanoic acid or C₆ to C₁₀ alkanedioic acid.The alkanol and acid moieties or mixtures thereof are preferablyselected such that they each have a melting point of below 20° C. Theseesters include isopropyl myristate, lauryl myristate, isopropylpalmitate, di-isopropyl sebacate and di-isopropyl adipate.

[0068] Suitable liquid aromatic esters, preferably having a meltingpoint of below 20° C., include fatty alkyl benzoates. Examples of suchesters include suitable C₈ to C₁₈ alkyl benzoates or mixtures thereof,including in particular C₁₂ to C₁₅ alkyl benzoates eg those availableunder the trademark Finsolv. Other suitable aromatic esters includealkyl naphthalates, alkyl salicylates and aryl benzoates of MP <20° C.Incorporation of such aromatic esters as at least a fraction of thehydrophobic carrier liquid can be advantageous, because they can raisethe average refractive index of volatile-silicone-containing carriers,and thereby render it easier to obtain translucent or transparentformulations.

[0069] Further instances of suitable hydrophobic carriers compriseliquid aliphatic ethers derived from at least one fatty alcohol, such asmyristyl ether derivatives e.g. PPG-3 myristyl ether or lower alkylethers of polygylcols such as an ether having named as PPG-14 butylether by the CTFA.

[0070] Aliphatic alcohols which are liquid at 20° C. and boil at above100° C. provide an essential constituent of the instant inventionformulations, and especially desirably those which are clearlywater-immiscible. Such alcohols can often constitute from 10% or 15% to30% or 55% by weight of the cosmetic composition.

[0071] Silicon-free liquids can constitute from 0-100% of the residue ofthe water-immiscible liquid carrier, i.e. other than saidabove-mentioned essential aliphatic alcohols, but it is preferred thatsilicone oil is present and that the amount of silicon-free constituentspreferably constitutes up to 50 or 60% and in many instances from 10 to60% by weight, eg 15 to 30% or 30 to 50% by weight, of thewater-immiscible carrier liquid.

[0072] As will be explained in more detail below, in cosmeticcompositions herein, the structured water-immiscible carrier liquid maybe the continuous phase in the presence of a dispersed second phase,which may comprise a suspension of particulate solid forming asuspension stick or a dispersion of droplets of a lypohobic liquid. Sucha solid may be a particulate antiperspirant or deodorant active orpigment. Such a disperse liquid phase may comprise a solution of theaforementioned active or actives in water or other hydrophilic ielypophobic solvent.

[0073] As mentioned hereinabove, in accordance with the first aspect,the invention requires a CDP structurant to structure a carrier oil thatcomprises a monohydric alcohol. A cosmetic active is present in cosmeticcompositions and other materials may also be present depending on thenature of the composition. The various materials will now be discussedby turn and some preferred features and possibilities will be indicated.

[0074] The proportion of the CDP structurant in a composition of thisinvention is likely to be from 0.1 to 15% by weight of the wholecomposition and preferably from 0.1 up to 10%. Its weight proportionmore commonly is at least 0.3% and in many instances not more than 5%.In some especially desirable embodiments, the amount of CDP structurantis from 0.5% to 3.5% or 5%. It will be recognised that for anyparticular CDP, its maximum proportion in the composition will vary inaccordance with its solubility in the selected monohydric alcohol andthe conditions prevailing during the dissolution process, such astemperature. Herein, unless other wise stated, a % for the CDP is byweight based on the entire composition.

[0075] If the composition is an emulsion with a separate disperse phase,the amount of structurant compound(s) is likely to be from 0.3 to 20% byweight of the continuous phase, more likely from 0.6% to 8% of thisphase. In some highly desirable embodiments the hydrophobic carriercontinuous phase contains from 2 to 5% by weight of the CDP.

[0076] Liquid Disperse Phase in Emulsions

[0077] If the composition is an emulsion in which the cyclo dipeptideacts as a structurant in the hydrophobic continuous phase, the emulsionwill contain a more polar or lypophobic disperse phase. The dispersephase may be a solution of an active ingredient.

[0078] The hydrophilic disperse phase in an emulsion commonly compriseswater as solvent and can comprise one or more water soluble or watermiscible liquids in addition to or in replacement of water. Theproportion of water in an emulsion according to the present invention isoften selected in the range of up to 60%, and particularly from 10% upto 40% or 50% of the whole formulation.

[0079] One class of water soluble or water-miscible liquids comprisesshort chain monohydric alcohols, e.g. C₁ to C₄ and especially ethanol orisopropanol, which can impart a deodorising capability to theformulation. Ethanol gives a cooling effect on application to skin,because it is very volatile. It is preferred that the content of ethanolor any other monohydric alcohol with a vapour pressure above 1.3 kPa (10mmHg) is not over 15% better not over 8% by weight of the composition.

[0080] A further class of hydrophilic liquids comprises diols or polyolspreferably having a melting point of below 40° C., or which are watermiscible. Examples of water-soluble or water-miscible liquids with atleast one free hydroxy group include ethylene glycol, 1,2-propyleneglycol, 1,3-butylene glycol, hexylene glycol, diethylene glycol,dipropylene glycol, 2-ethoxyethanol, diethylene glycol monomethylether,triethyleneglycol monomethylether and sorbitol. Especially preferred arepropylene glycol and glycerol.

[0081] In an emulsion the disperse phase is likely to constitute from 5to 80 or 85% of the weight of the composition preferably from 5 to 50 or65% more preferably from 25 or 35% up to 50 or 65%, while the continuousphase with the structurant therein provides the balance from 15 or 35%up to 95% of the weight of the composition. Compositions with highproportion of disperse phase, i.e. from 65 to 85% disperse phase, may beadvantageous because they can give good hardness even though theconcentration of structurant may be only a small percentage of the totalcomposition. However, compositions with a lower proportion of dispersephase can also be advantageous because they tend to offer a drier andwarmer feel.

[0082] An emulsion composition will generally include one or moreemulsifying surfactants which may be anionic, cationic, zwitterionicand/or nonionic surfactants. The proportion of emulsifier in thecomposition is often selected in the range up to 10% by weight and inmany instances from 0.1 or 0.25 up to 5% by weight of the composition.Most preferred is an amount from 0.1 or 0.25 up to 3% by weight.Nonionic emulsifiers are frequently classified by HLB value. It isdesirable to use an emulsifier or a mixture of emulsifiers with anoverall HLB value in a range from 2 to 10 preferably from 3 to 8.

[0083] It may be convenient to use a combination of two or moreemulsifiers which have different HLB values above and below the desiredvalue. By employing the two emulsifiers together in appropriate ratio,it is readily feasible to attain a weighted average HLB value thatpromotes the formation of an emulsion.

[0084] Many suitable emulsifiers of high HLB are nonionic ester or etheremulsifiers comprising a polyoxyalkylene moiety, especially apolyoxyethylene moiety, often containing from about 2 to 80, andespecially 5 to 60 oxyethylene units, and/or contain a polyhydroxycompound such as glycerol or sorbitol or other alditol as hydrophilicmoiety. The hydrophilic moiety can contain polyoxypropylene. Theemulsifiers additionally contain a hydrophobic alkyl, alkenyl or aralkylmoiety, normally containing from about 8 to 50 carbons and particularlyfrom 10 to 30 carbons. The hydrophobic moiety can be either linear orbranched and is often saturated, though it can be unsaturated, and isoptionally fluorinated. The hydrophobic moiety can comprise a mixture ofchain lengths, for example those deriving from tallow, lard, palm oil,sunflower seed oil or soya bean oil. Such nonionic surfactants can alsobe derived from a polyhydroxy compound such as glycerol or sorbitol orother alditols. Examples of emulsifiers include ceteareth-10 to -25,ceteth-10-25, steareth-10-25 (i.e. C₁₆ to C₁₈ alcohols ethoxylated with10 to 25 ethylene oxide residues) and PEG-15-25 stearate or distearate.Other suitable examples include C₁₀-C₂₀ fatty acid mono, di ortri-glycerides. Further examples include Cl₈-C₂₂ fatty alcohol ethers ofpolyethylene oxides (8 to 12 EO).

[0085] Examples of emulsifiers, which typically have a low HLB value,often a value from 2 to 6 are fatty acid mono or possibly diesters ofpolyhydric alcohols such as glycerol, sorbitol, erythritol ortrimethylolpropane. The fatty acyl moiety is often from C₁₄ to C₂₂ andis saturated in many instances, including cetyl, stearyl, arachidyl andbehenyl. Examples include monoglycerides of palmitic or stearic acid,sorbitol mono or diesters of myristic, palmitic or stearic acid, andtrimethylolpropane monoesters of stearic acid.

[0086] A particularly desirable class of emulsifiers comprisesdimethicone copolymers, namely polyoxyalkylene modifieddimethylpolysiloxanes. The polyoxyalkylene group is often apolyoxyethylene (POE) or polyoxypropylene(POP) or a copolymer of POE andPOP. The copolymers often terminate in C₁ to C₁₂ alkyl groups.

[0087] Suitable emulsifiers and co-emulsifiers are widely availableunder many trade names and designations including Abil™, Arlacel™,Brij™, Cremophor™, Dehydrol™, Dehymuls™, Emerest™, Lameform™, Pluronic™,Prisorine™, Quest PGPH™, Span™, Tween™, SF1228, DC3225C and Q2-5200.

[0088] Cosmetic Actives

[0089] The cosmetic actives employable herein can compriseantiperspirant or deodorant actives or pigments.

[0090] Antiperspirant Actives

[0091] The composition preferably contains an antiperspirant active.Antiperspirant actives, are preferably incorporated in an amount of from0.5-60%, particularly from 5 to 30% or 40% and-especially from 5 or 10%to 30 or 35% of the weight of the composition.

[0092] Antiperspirant actives for use herein are often selected fromastringent active salts, including in particular aluminium, zirconiumand mixed aluminium/zirconium salts, including both inorganic salts,salts with organic anions and complexes. Preferred astringent saltsinclude aluminium, zirconium and aluminium/zirconium halides andhalohydrate salts, such as chlorohydrates and activated aluminiumchlorohydrates.

[0093] Aluminium halohydrates are usually defined by the general formulaAl₂(OH)_(x)Qy.wH₂ 0 in which Q represents chlorine, bromine or iodine, xis variable from 2 to 5 and x+y=6 while wH₂O represents a variableamount of hydration. Especially effective aluminium halohydrate salts,known as activated aluminium chlorohydrates, are described in EP-A-6739(Unilever NV et al), the contents of which specification is incorporatedherein by reference. Some activated salts do not retain their enhancedactivity in the presence of water but are useful in substantiallyanhydrous formulations, i.e. formulations which do not contain adistinct aqueous phase.

[0094] Zirconium actives can usually be represented by the empiricalgeneral formula: ZrO (OH)_(2n-nz)B_(z).wH₂ 0 in which z is a variable inthe range of from 0.9 to 2.0 so that the value 2n-nz is zero orpositive, n is the valency of B, and B is selected from the groupconsisting of chloride, other halide, sulphamate, sulphate and mixturesthereof. Possible hydration to a variable extent is represented by wH₂0. Preferable is that B represents chloride and the variable z lies inthe range from 1.5 to 1.87. In practice, such zirconium salts areusually not employed by themselves, but as a component of a combinedaluminium and zirconium-based antiperspirant.

[0095] The above aluminium and zirconium salts may have co-ordinatedand/or bound water in various quantities and/or may be present aspolymeric species, mixtures or complexes. In particular, zirconiumhydroxy salts often represent a range of salts having various amounts ofthe hydroxy group. Zirconium aluminium chlorohydrate may be particularlypreferred.

[0096] Antiperspirant complexes based on the above-mentioned astringentaluminium and/or zirconium salts can be employed. The complex oftenemploys a compound with a carboxylate group, and advantageously this isan amino acid. Examples of suitable amino acids include dl-tryptophan,dl-β-phenylalanine, dl-valine, dl-methionine and β-alanine, andpreferably glycine which has the formula CH₂ (NH₂) COOH.

[0097] It is highly desirable to employ complexes of a combination ofaluminium halohydrates and zirconium chlorohydrates together with aminoacids such as glycine, which are disclosed in U.S. Pat. No. 3,792,068(Luedders et al). Certain of those Al/Zr complexes are commonly calledZAG in the literature. ZAG actives generally contain aluminium,zirconium and chloride with an Al/Zr ratio in a range from 2 to 10,especially 2 to 6, an Al/Cl ratio from 2.1 to 0.9 and a variable amountof glycine. Actives of this preferred type are available from Westwood,from Summit and from Reheis.

[0098] Other actives which may be utilised include astringent titaniumsalts, for example those described in GB 2299506A.

[0099] The proportion of solid antiperspirant salt in a suspensioncomposition normally includes the weight of any water of hydration andany complexing agent that may also be present in the solid active.However, when the active salt is incorporated in solution in ahydrophilic solvent such as a glycol, its weight commonly excludes anywater present.

[0100] If the composition is in the form of an emulsion theantiperspirant active will be dissolved in the disperse phase. In thiscase, the antiperspirant active will often provide from 3 to 60% byweight of the disperse phase, particularly from 10% or 20% up to 55% or60% of that phase. Alternatively, the composition may take the form of asuspension in which antiperspirant active in particulate form issuspended in the water-immiscible liquid carrier. Such a compositionwill probably not have any separate aqueous phase present and mayconveniently be referred to as “substantially anhydrous” although itshould be understood that some water may be present bound to theantiperspirant active or as a small amount of solute within thewater-immiscible liquid phase. In such compositions, the particle sizeof the antiperspirant salts often falls within the range of 0.1 to 200μm with a mean particle size often from 3 to 20μm. Both larger andsmaller mean particle sizes can also be contemplated such as from 20 to50μm or 0.1 to 3μm.

[0101] Deodorant Actives

[0102] Suitable deodorant actives can comprise deodorant effectiveconcentrations of antiperspirant metal salts, deoperfumes, and/ormicrobicides, including particularly bactericides, such as chlorinatedaromatics, including biguanide derivatives, of which materials known asIgasan DP300™ (triclosan), Tricloban™, and Chlorhexidine warrantspecific mention. A yet another class comprises biguanide salts such asare available under the trade mark Cosmosil™. Deodorant actives arecommonly employed at a concentration of from 0.1 to 25% by weight.

[0103] Optional Ingredients

[0104] Other optional ingredients include wash-off agents, often presentin an amount of up to 10% w/w to assist in the removal of theformulation from skin or clothing. Such wash-off agents are typicallynonionic surfactants such as esters or ethers containing a C₈ to C₂₂alkyl moiety and a hydrophilic moiety which can comprise apolyoxyalkylene group (POE or POP) and/or a polyol.

[0105] A further optional constituent of the formulation comprises oneor more further structurants which can be employed in addition to thecyclo dipeptide. Herein, the CDP may be the primary structurant, bywhich is meant that is employed at a concentration that is higher thanthat of the further structurant. However, in some advantageousembodiments, the further structurant may be present in an amount that isat least that of the CDP. In such advantageous embodiments, the CDP isacting to moderate the properties of the further structurant such thatthe properties using the combined structurant system are superior in atleast one desirable respect to using the further structurant alone. Theamount of such further structurants in the formulation is often fromzero to not more than 15% of the formulation. In some instances, thefurther structurant is present in a weight ratio to the CDP of from 10:1to 1:10.

[0106] The further structurants employable herein can be non-polymericor polymeric. Solid linear fatty alcohol and/or a wax may be includedbut are not preferred. In anhydrous compositions notably antiperspirantswhich are suspension sticks, non-polymeric further structurants,sometimes referred to as gellants, can be selected from fatty acids orsalts thereof, such as stearic acid or sodium stearate or 12-hydroxystearic acid. Linear fatty acids are preferably not used in aqueoussticks, e.g. aqueous emulsion sticks because they can form insolubleprecipitates with aluminium ions. Other suitable gellants can comprisedibenzylidene alditols, e.g. dibenzylidene sorbitol. Further suitablegellants can comprise selected N-acyl amino acid derivatives, includingester and amide derivatives, such as N-lauroyl glutamic aciddibutylamide, which gellants can be contemplated in conjunction with12-hydroxy stearic acid or an ester or amide derivative thereof. Stillfurther gellants include amide derivatives of di or tribasic carboxylicacids, such as alkyl N,N′ dialkylsuccinamides, e.g. dodecylN,N′-dibutylsuccinamide. When employing further structurants comprisingN-acyl amino acid derivatives, in some highly desirably formulationstheir weight ratio to CDP is selected in the range of 1:1 to 6:1.

[0107] Polymeric structurants which can be employed as furtherstructurants can comprise organo polysiloxane elastomers such asreaction products of a vinyl terminated polysiloxane and a cross linkingagent or alkyl or alkyl polyoxyalkylene-terminated poly (methylsubstituted) or poly (phenyl substituted) siloxanes. A number ofpolyamides have also been disclosed as structurants for hydrophobicliquids. Polymers containing both siloxane and hydrogen bonding groups,which might be used as secondary structurants, have been disclosed in WO97/36572 and WO 99/06473. If an aqueous disperse phase is present,polyacrylamides, polyacrylates or polyalkylene oxides may be used tostructure or thicken this aqueous phase.

[0108] It is highly desirable that any further structurant employedherein is itself fibre-forming, that is to say forms a fibrous structurewithin the hydrophobic phase. Most preferably the fibre-formingstructurant is one in which the fibrous structure is not visible to thehuman eye.

[0109] Fatty alcohols which are solid at room temperature of 20° C.,such as linear monohydric alkanols containing at least 12 carbons e.g.stearyl alcohol or behenyl alcohol, lead to deposits with an opaquewhite appearance and are preferably substantially absent, by which wemean present in an amount of no more than 3% by weight of thecomposition, more preferably less than 1% and most preferably are notincorporated specifically, ie 0%. As already mentioned, fatty alcoholsare often regarded as coming within the general category of waxymaterials. More generally the term “wax” is conventionally applied to avariety of materials and mixtures (including some fatty alcohols) whichhave some diversity in chemical structure but similarity in physicalproperties. The term generally denotes materials which are solid at 30°C., often also solid up to 40° C., having a waxy appearance or feel, butwhich gradually soften and eventually melt to a mobile liquid at atemperature below 95° C. usually below 90° C.

[0110] Possibly the composition does not include more than 3% of anymaterial which is a wax, ie a solid at 30° C. but softens at an elevatedtemperature and at 95° C. is molten and soluble in the water-immiscibleliquid, yet which is unable to form a network of fibres therein oncooling to 20° C.

[0111] The compositions herein can incorporate one or more cosmeticadjuncts in amounts conventionally contemplatable for cosmetic solids orsoft solids. Such cosmetic adjuncts can include skin feel improvers,such as small particle inorganic mineral substances like talc, finelydivided silica and/or bentonite or similar clays, or finely dividedpolyethylene, for example in an amount of up to about 10%; skin benefitagents such as allantoin or lipids, for example in an amount of up to5%; colours; skin cooling agents other than the already mentionedalcohols, such a menthol and menthol derivatives, often in an amount ofup to 2%, all of these percentages being by weight of the composition. Acommonly employed adjunct is a perfume, which is normally present at aconcentration of from 0 to 4% and in many formulations from 0.25 to 2%by weight of the composition.

[0112] Product Form

[0113] The sticks produced employing the CDP structurants can be eitheropaque or translucent or even transparent, depending at least partly onthe extent to which the refractive indices (RI) of the appropriateingredients are matched. Translucent or transparent formulations arepossible in respect of the invention formulations because the CDPstructurant forms a fibrous structure within the liquid hydrophobiccarrier that is not seen by the human eye. By matched herein is meantthat the difference between the refractive indices is less than 0.005and preferably less than 0.002. In suspension sticks, to achieve atleast translucency without using exclusively sub-micron sized particles,it is necessary to match the RI of the suspended cosmetic active, eg theparticulate antiperspirant salt, with the RI of the suspending carrieroil mixture. This can be assisted by a suitable choice of oils, and inparticular mixtures containing those having an RI of above 1.46, such asfrom 1.46 to 1.56. In regard to the suspended particulates, RI matchingcan be assisted by controlling the particle size distribution, andparticularly by not permitting an excess proportion of 1 to 10 micronparticles and advantageously by avoiding the manufacture of hollowsphere antiperspirant actives or subsequently removing the hollows.Matching can be further assisted by modifying the RI of the suspendedcosmetic active, such as an aluminium-containing antiperspirant activeby post treating it with water (re-hydration) or by retaining acomparatively high water content during the manufacture process. Inemulsion formulations, the relevant ingredients to RI match comprise thedisperse and continuous liquid phases.

[0114] It is highly desirable to employ RI matching as indicated abovein conjunction with the exclusion, to the extent necessary, ofadditional suspended materials having a different refractive index fromthe suspending medium, such as for example a suspended filler oradditional cosmetic active, to enable the resultant composition totransmit at least 1% light (in the test described hereinafter).

[0115] Mechanical Properties and Product Packages

[0116] The compositions of this invention are structured liquids and arefirm in appearance. A composition of this invention will usually bemarketed as a product comprising a container with a quantity of thecomposition therein, where the container has an aperture for thedelivery of composition, and means for urging the composition in thecontainer towards the delivery aperture. Conventional containers takethe form of a barrel of oval cross section with the delivery aperture atone end of the barrel.

[0117] A composition of this invention may be sufficiently rigid that itis not apparently deformable by hand pressure and is suitable for use asa stick product in which a quantity of the composition in the form of astick is accommodated within a container barrel having an open end atwhich an end portion of the stick of composition is exposed for use. Theopposite end of the barrel is often closed.

[0118] Generally the container will include a cap for its open end and acomponent part which is sometimes referred to as an elevator or pistonfitting within the barrel and capable of relative axial movement alongit. The stick of composition is accommodated in the barrel between thepiston and the open end of the barrel. The piston is used to urge thestick of composition along the barrel. The piston and stick ofcomposition may be moved axially along the barrel by manual pressure onthe underside of the piston using a finger or rod inserted within thebarrel. Another possibility is that a rod attached to the pistonprojects through a slot or slots in the barrel and is used to move thepiston and stick. Preferably the container also includes a transportmechanism for moving the piston comprising a threaded rod which extendsaxially into the stick through a correspondingly threaded aperture inthe piston, and means mounted on the barrel for rotating the rod.Conveniently the rod is rotated by means of a hand-wheel mounted on thebarrel at its closed end, i.e. the opposite end to the delivery opening.

[0119] The component parts of such containers are often made fromthermoplastic materials, for example polypropylene or polyethylene.Descriptions of suitable containers, some of which include furtherfeatures, are found in U.S. Pat. Nos. 4,865,231, 5,000,356 and5,573,341.

[0120] Composition Preparation

[0121] Compositions of this invention can be produced by process similarto conventional processes for making cosmetic solids. Such processesinvolve forming a heated mixture of the structurant in the carrier oil,in this case the monohydric alcohol and optionally together with afraction or even all of any other oil, at a temperature which issufficiently elevated that all the structurant dissolves, pouring thatmixture into a mould, which may take the form of a dispensing container,and then cooling the mixture whereupon the structurant solidifies into anetwork of fibres extending through the water-immiscible liquid phase.The employment of the monohydric alcohol in the continuous carrierenables the benefits of higher CDP concentration and reduced gellingtemperature to be attained

[0122] A convenient process sequence for a composition which is asuspension comprises first forming a solution of the structurant in themonohydric alcohol and optionally a fraction of or even all thewater-immiscible liquids. This is normally carried out by agitating themixture at a temperature sufficiently high that all the structurantdissolves (the dissolution temperature) such as a temperature in a rangefrom 50 to 140° C. Thereafter, the particulate constituent, for exampleparticulate antiperspirant active, is blended with the hot mixture. Thismay be done slowly, and/or the particulate solid preheated, in order toavoid premature gelation. The resulting blend is then introduced into adispensing container such as a stick barrel. This is usually carried outat a temperature 5 to 30° C. above the setting (gelling) temperature ofthe composition. The container and contents are then cooled to ambienttemperature. Cooling may be brought about by nothing more than allowingthe container and contents to cool. Cooling may be assisted by blowingambient or even refrigerated air over the containers and their contents.

[0123] In a suitable procedure for making emulsion formulations, asolution of the structurant in the continuous carrier phase is preparedat an elevated temperature just as for suspension sticks. If anyemulsifier is being used, this is conveniently mixed into this liquidphase. Separately, an aqueous or hydrophilic disperse phase is preparedby introduction of antiperspirant active into the liquid part of thatphase (if this is necessary: antiperspirant actives can sometime besupplied in aqueous solution which can be utilised as is). If possible,this solution of antiperspirant active which will become the dispersephase is preferably heated to a temperature similar to that of thecontinuous phase with structurant therein, but without exceeding theboiling point of the solution, and then mixed with the continuous phase.Alternatively, the solution is introduced at a rate which maintains thetemperature of the mixture. If it is necessary to work at a temperatureabove the boiling temperature of the disperse phase, or at a temperaturewhere evaporation from this phase is significant, a pressurisedapparatus could be used to allow a higher temperature to be reached.After the two phases are mixed, the resulting mixture is filled intodispensing containers, typically at a temperature 5 to 30° C. above thesetting temperature of the composition, and allowed to cool as describedabove for suspension sticks.

[0124] Many of the cosmetic compositions according to the presentinvention employ a mixture of at least one hydrophobic cosmetic oil(carrier fluid) with the monohydric alcohol. In some convenientpreparative routes, it is desirable to dissolve the CDP structurant inthe alcohol, optionally in conjunction with a minor proportion of analcohol having some water-miscibility and boiling point above thedissolution temperature of CDP in the alcoholic fluid. This enables theremainder of the carrier fluids to avoid being taken to the temperatureat which the CDP dissolves or melts. The proportion of the carrierfluids for dissolving the CDP is often from 15 to 85% by weight of thecarrier fluids, and particularly from 20 to 40% or 70%. In onevariation, the CDP structurant is first dissolved by heating to anelevated temperature with stirring in a mixture comprising themonohydric alcohol plus up to a quarter or even up to half of the totalof any water-immiscible cosmetic oil employed in the composition, andthere after mixing the solution of the CDP with the remainder of thecosmetic oil and the cosmetic active, such a particulate antiperspirantor an aqueous solution of an antiperspirant. The remainder of thecosmetic oil and of the cosmetic active are taken to a suitabletemperature such that the temperature of their mixture with the CDPsolution is still above the gelling temperature of the composition,preferably no more than 5 or 10° C. above the gelling temperature, whichmay have been determined in a previous trial.

[0125] Structurant Preparation

[0126] CDP structurants can be made by one or more of the generalpreparative routes published in the above-identified papers by Hanabusawith appropriately chosen reagents to obtain the desired substituentgroups R₁ and R₂ of the cyclo dipeptide, and/or by variations describedhereinbelow or the general method described herein to make the materialsCDP1 to CDP13.

[0127] One route of general applicability described by Hanabusacomprises the cyclisation of dipeptide ethyl esters under reflux in1,3,5-trimethyl benzene, the esters being obtained by catalytichydrogenation of the corresponding N-benzoylcarbonyl dipeptide ethylether with 10% Pd-C. In a variation thereof, ester groups in an existingester CDP can be replaced in a conventional transesterification processin the corresponding alcohol, eg 3,7-dimethyloctanol. Various of theCDPs are derivable indirectly from aspartame by esterifyingcyclo[(R)-phenylalanyl] that is obtainable by heating aspartame,preferably in the presence of a substantial excess of a low molecularweight aliphatic alcohol, such as isopropanol, under reflux for a longperiod. Desirably, the alcohol is employed in a weight ratio toaspartame of greater than 50:1 such as up to 100:1, and the reaction iscontinued for at least 10 hours at reflux temperature, such as from 15to 24 hours. During the reaction, the aspartame gradually dissolves. Oncooling, the resultant solution yields a white powder. Removal of thesolvent from the filtrate yields a solid which, after washing withacetone, provides a further amount of the white product, confirmed by acombined yield of the CDP precursor acid of 79%.

[0128] The precursor acid can be reacted with the relevant alcohol offormula R_(A)OH, preferably in a mole ratio to the precursor of at least1:1 to 10:1, particularly from 1.5:1 to 7:1 and especially at least 2:1in dimethyl sulphoxide, conveniently in a ratio of at least 4:1(vol:wt), preferably from 6:1 to 12:1, and preferably in the presence ofa promoter, such as a carbonyldiimidazole, in an amount preferably from0.5 to 2 moles of promoter per mole of precursor acid. The reaction isconveniently carried out at a mildly elevated temperature, such as up to60° C. and particularly from 40 to 60° C. for a period of at least 6hours and preferably from 9 to 24 hours. The resultant solution isquenched in excess ambient or cooler water, desirably after the solutionhas cooled to ambient, a solid precipitates and is filtered off, waterwashed until no residual diimidazole remained and then can be purifiedby washing with diethyl ether or toluene, and dried.

EXAMPLES

[0129] Preparation of CDP Structurants

[0130] The cyclo dipeptide structurants employed in the followingExamples and Comparisons were made by the following general methodemploying (2S-cis)-(-)-5-benzyl-3,6-dioxo-2-piperazine acetic acid(DOPAA) which was reacted with the alcohols specified in Table 1 below.

[0131] A 250 ml 3 necked round bottomed flask equipped with a stirrerwas charged with (2S-cis)-(-)-5-benzyl-3,6-dioxo-2-piperazine aceticacid (DOPAA) (18.4 mmol), and dimethyl sulfoxide (8mls per 1 g of DOPAA)was then introduced at laboratory ambient temperature (about 22° C.)with stirring. The DOPAA dissolved only partially.1,1′-carbonyldiimidazole (22 mmol) was then introduced with stirring inthe amount specified in the Table. Vigorous effervescence occurred andthe react mixture was left stirring at room temperature for 45 minutesafter which time the reaction mixture went clear. The specified alcohol(92 mmol) was stirred into the clear reaction mixture and maintained at50° C. overnight (between 16 and 20 hours), whereupon it was allowed tocool to ambient temperature (about 22° C.), and poured into water,producing a precipitate which was filtered off and washed with furtherquantities of water until any residual diimidazole had been removed (asshown by ¹Hnmr). The washed precipitate was then washed with diethylether. The washed product was dried in a vacuum oven to constant weightand its melting point determined, the results quoted herein beingobtained by DSC with a heating rate of 10° C./min, except for thosemarked ^(ET), which were obtained using a an Electrothermal 9109 digitalmelting point measuring apparatus. TABLE 1 Purity Melting CDP Alcohol %Point ° C. CDP1 (1S,2R,5S)-(+) Menthol 98.7 238 CDP2 Thymol 99.3 212CDP3 1R,2R,3R,5S-(−)-iso- 68 >200 pinocamphenol CDP43,5-dimethyl-cyclohexanol 94 212 CDP5 phenol 99.7 246 CDP6butyl-4-hydroxy benzoate 98.5 217 CDP7 iso-propanol 98.5 215 CDP8n-propanol 98.2 >200 CDP9 4-t-butylphenol 99.1 237 CDP10 carveol 65.0215^(ET) CDP11 carvacrol 99.1 229^(ET) CDP125,6,7,8-tetrahydronaphth-2-ol 99.3 220^(ET) CDP13 2-isopropoxyphenol98.8 178^(ET)

[0132] Materials

[0133] The materials used in gel studies or the preparation of cosmeticformulations, and their proprietary names, other than the structurantsCDP1 to CDP9, are summarised in Table 2: TABLE 2 Abrev CFTA name TradeName/supplier Monohydric Alcohols  1 ISA Isostearyl Alcohol Pricerine3515 ™ - Uniqema  2 ODA Octyl Dodecanol Eutanol G ™ - Cognis  3 BMABenzyl Alcohol Acros  4 8MA octyl Alcohol Sigma  5 10MA decyl AlcoholSigma  6 ICA iso-cetyl Alcohol Eutanol G16 - Cognis Water-immiscible oil 7 TN C₁₂₋₁₅ alkyl Finsolv TN ™ from Finetex benzoate Inc  8 245Cyclomethicone DC 245 ™ - Dow Corning Inc  9 364 Hydogenated Silkflo 364NF ™ - Albemarle Polydecene 10 704 1,1,5,5-tetraphenyl DC704 ™: DowCorning Inc trisiloxane Auxiliary Structurant 11 GP1 N-lauroyl-L-Gp-1 ™Ajinomoto Co Inc glutamic acid Di-n- butylamide 18 DBSdibenzylidene Roquette sorbitol 19 HSA 12-hydroxystearic 12-HSA(CasChem) acid 20 930 Polyamide Versamid 930 ™ (Cognis) Emulsifier 12EM90 Dimethicone Abil EM90 ™ - Th. Goldschmidt Copolyol AG 21 P135dipolyhydroxy- Arlacel p135 ™ (Uniquema) stearate Cosmetic Active 13R908 Al/Zr Reach 908 ™ - Reheis Inc Tetrachlorohydrex glycine complex 14A418 Milled A418 ™ - Summit Macrospherical AACH 15 Z50 50% aqueousZirconal 50 ™ - BK Giulini solution of Al/Zr pentachlorohydrate 16 R67*Water-modified Rezal 67 ™ modified in-house AZAG 22 36GP solid Al/Zrtetra- Rezal 36GP ™ Reheis Inc chlorhydrex glycine 23 P5G Al/Zrpentachloro- P5G ™ (BK Giulini) hydrex glycine complex (RI 1.530)Water-miscible liquids 17 GOH Glycerin Glycerol - Aldrich 24 PGpropane-1,2-diol Fisher 25 DPG di(propane-1,2- Fisher diol) 26 TPnBtri(1,2-propane- Dowanol TPnB ™ - Dow Corning diol) n-butylether IncOther Ingredients 27 H30 silica H30 ™ - Wacker-Chemie GmbH 28 H30Rsilica H30RX ™ - Wacker-Chemie GmbH X 29 H18 silica H18 ™ -Wacker-Chemie GmbH

Example 1

[0134] Structured Gels

[0135] In this Example, gels were made or attempted to be made in anumber of representative organic solvents, using the structurants CDP1to CDP13.

[0136] The gels were prepared in 30 ml clear glass bottles. The solventand gelling agent were weighed directly into the bottle to give a totalmixture weight of 10 g. A small Teflon™ stirrer bar was placed in thebottle and the mixture stirred and heated until the cyclo dipeptide haddissolved. The bottle was then removed from the heat and the solutionallowed to cool and gel under quiescent conditions.

[0137] The ease of gel formation was assessed by determining for each ofthe cosmetic base formulations the temperature at which the CDPstructurant dissolved in the chosen oil(s) and if dissolution wasobserved, the temperature at which a gel formed on cooling theformulation. The results are summarised in Table 3.

[0138] These Examples and comparisons demonstrate the relative ease ordifficulty of forming gelled cosmetic base formulations, depending onwhich oils are employed during the dissolution of the CDP structurantand the subsequent formation of a gel as the composition cools. Theresults are representative of corresponding formulations in which acosmetic active is also introduced. TABLE 3 Example/Comp 1.1 1.2 1.3 1.41.5 1.6 1.7 C1.1 C1.2 C1.3 C1.4 Ingredients % by weight CDP1 1.5 1.5 1.51.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1-ISA 98.5 49.25 49.25 49.25 49.25 2-ODA98.5 3-BMA 7.4 7-TN 49.25 98.5 8-245 49.25 98.5 9-364 49.25 98.5 10-70449.25 91.1 98.5 Gel Formed? yes yes yes yes yes yes yes no yes yes noDiss'n Temp ° C. 120 131 138 105 125 123 148 dnd 142 ˜150 dnd 140Gelling Temp ° C. 35 65 65 43 41 46 75 — 79 126 — Example/Comp 1.8 1.91.10 1.11 1.12 1.13 1.14 1.15 1.16 1.17 1.18 1.19 1.20 Ingredients % byweight CDP2 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 3.75 4.0 1-ISA98.5 49.25 49.25 49.25 24.62 49.25 12.02 26.88 2-ODA 24.62 3-BMA 7.412.02 9.60 4-8MA 24.62 5-10MA 24.62 6-ICA 98.5 7-TN 49.25 6.72 8-24549.25 52.8 9-364 49.25 10-704 49.25 73.88 73.88 73.88 73.88 91.1 72.21Properties Gel Formed yes yes yes yes yes yes yes yes yes yes yes yesyes Diss'n Temp ° C. 111 115 137 127 136 118 114 114 134 136 130 119 130Gellng Temp ° C. 29 33 58 50 58 25 30 28 62 56 61 55 66 Example/Comp1.21 1.22 C1.5 C1.6 C1.7 C1.8 1.23 C1.9 1.24 1.25 1.26 1.27 Ingredient %by weight CDP2 15.0 3.0 1.5 1.5 1.5 3.75 CDP5 1.5 1.5 CDP6 1.5 1.5 1.51.5 1-ISA 51.0 19.4 98.5 49.25 49.25 3-BMA 34.0 9.7 24.62 14.77 8-24598.5 7-TN 98.5 49.25 9-364 10-704 67.9 98.5 98.5 73.88 98.5 49.25 83.73Properties Gel Formed? yes yes yes no yes yes yes no yes yes yes yesDiss'n Temp ° C. 123 130 133 dnd 148 dnfd 134 dnd 140 145 130 140 135Gelling Temp ° C. 69 70 84 98 ˜120 69 — 62 86 78 76 Example/Comp C1.10C1.11 1.28 1.29 1.30 1.31 1.32 1.33 1.34 1.35 C1.12 1.36 1.37 C1.13Ingredient % by weight CDP6 1.5 1.5 CDP7 1.5 1.5 CDP8 1.5 CDP3 1.5 1.5CDP4 1.5 CDP10 1.5 1.5 1.5 CDP11 1.5 1.5 1.5 1-ISA 98.5 24.62 98.5 98.549.25 98.5 98.5 24.62 98.5 3-BMA 24.62 7-TN 98.5 49.25 9-364 10-704 98.573.88 73.88 98.5 73.88 98.5 Properties Gel Formed? yes yes yes yes yesyes yes yes yes yes yes yes yes yes Diss'n Temp ° C. dnfd dnfd 113 134107 138 150 130 111 139 dnfd 110 90 146 Gelling 143 120 45 77 49 25 3957 38 66 94 98 25 118 Temp ° C. Composition (%) 1.38 C1.14 1.39 1.40C1.15 1.41. C1.16 1.42 C1.17 1.43 C1.18 CDP12 1.5 1.5 CDP13 1.5 1.5 1.5CDP14 1.5 1.5 CDP15 0.5 0.5 1.5 1.5 1-ISA 98.5 24.62 99.5 3-BMA 24.6224.62 24.62 10-704 73.88 98.5 73.88 98.5 73.8 98.5 99.5 73.88 98.5 GelFormed yes yes yes yes yes yes no yes no yes no Dissolution 121 dnfd 8595 102 148 DND 129 DND 128 DND Temperature (° C.) 150 Gelling 58 128 2525 79 95 42 75 Temperature (° C.)

[0139] In Table 3 above, dnd indicates that the structurant did notdissolve, and dnfd that it did not fully dissolve, in each case at 150°C. unless otherwise indicated.

[0140] From Table 3, it can be seen that the employment of the specifiedmonohydric alcohols, viz materials (1) to (6), enabled the resultantcomposition to gel at a lower temperature. Thus, for example, acomparison of Ex 1.2 with C1.1 shows that the CDP dissolved in theinvention mixture at 131° C., but had not dissolved at 140° C. in solelythe volatile silicone. Similar improvements can be seen by comparing Ex1.3 or 1.4 with C1.4 and C1.3 respectively. Of course, where thestructurant had not dissolved, it could not subsequently form adistributed network through the carrier liquid and hence was not able toform a gel. Where it did dissolve, though at a higher temperature as inC1.3, the composition gelled at a much higher temperature ofsignificantly over 100° C. compared with the gelling temperature of thedirectly comparable invention composition, Ex 1.3. Ex 1.21 shows theformation of a concentrated solution/gel that can subsequently bediluted with other cosmetic oils during stick preparation.

Examples 2 to 5

[0141] Cosmetic Stick Formulations

[0142] A number of cosmetic stick compositions were prepared, containingthe ingredients specified in Tables 4 to 10 below. Their properties weremeasured by the methods described hereinafter and at the times indicatedin the summaries.

Example 2

[0143] Opaque Suspension Sticks

[0144] In Example 2, opaque sticks were made by dissolving the specifiedcyclo dipeptide structurant in isostearyl alcohol whilst with heated andstirring using an overhead paddle stirrer until complete dissolution hadoccurred. In formulations additionally containing GP1, the latter wasdissolved into solution of the cyclo dipeptide structurant at atemperature of about 5 to 10° C. lower. The remaining carrier oils wereheated to approximately 50° C. and stirred using a stirrer bar and thedesired solid antiperspirant active was introduced slowly and withgentle stirring into them. When all the active had been added, themixture was sheared using a Silverson mixer at 7000 rpm for 5 minutes toensure the active was fully dispersed. The active/oil mixture was thenheated in an oven to 85° C. and mixed into the structurant solutionwhich had been allowed to cool to 90° C. The temperature of the stirredmixture was kept at 85° C. until it was poured into conventionalcommercial 50 g stick barrels and allowed to cool except forformulations containing GP1 which were poured at approximately 75° C.

[0145] The formulations and properties of the sticks are summarised inTable 4 below. TABLE 4 Example No 2.1 2.2 2.3 2.4 2.5 Ingredient % byweight CDP2 2.5 2.5 1.5 1 CDP3 1.5 1.ISA 35.75 35.75 30 28.2 30 7 TN35.75 20.9 8.245 20.9 10.704 35.75 40 40 11.GP1 2.5 3.0 2.5 13.R908 26.026.0 26.0 26.0 26.0 Properties Hardness (mm) 16.5 15.2 13.8 18.6 14.3pay.off (g) at t_(o) 0.35 0.25 0.31 0.27 0.3 on WetorDry whiteness t =24 hr 13 16 14 27 20 on WetorDry pay.off (g) at t_(o) 0.99 0.63 0.820.63 1.08 on wool whiteness t = 24 hr 17 17 16 15 20 on wool

[0146] From Table 4, it can be seen that sticks of acceptable firmnesscan be obtained using the invention structurants at comparatively lowconcentrations of the structurant and also in the presence of anadditional structurant, also at a low concentration.

Example 3

[0147] Transparent Suspension Sticks

[0148] The sticks in this Example were made using the process of Example3 together with a preparatory step. In the preparatory step, the RI ofthe antiperspirant active was first measured using a standard procedure(Becke line test). The proportions of each of the carrier oils were thendetermined (through calculation and measurement) such that their weightaveraged refractive index was closely matched to that of the active. InExample 3.8, the CDP structurant was fully dissolved in the mixture ofmonohydric alcohols before being mixed with the remainder of the carrieroils and subsequently with the antiperspirant active. The formulationsare summarised in Table 5 below. TABLE 5 Example No 3.1 3.2 3.3 3.4 3.53.6 3.7 3.8 3.9 Ingredient % by weight CDP2 1.51 1.5 1.5 1.0 2.81 CDP40.70 CDP1 1.0 CDP5 1.5 CDP9 3.0 1-ISA 18.34 17.61 17.36 17.55 17.6117.36 16.71 8.81 3-BMA 8.81 19.68 7-TN 12.21 22.83 10-704 55.03 52.8952.14 52.7 52.89 52.14 54.29 42.36 29.47 11-GP1 3.0 4.0 4.05 3.5 4.0 3.014-A418 25.12 25.0 25.0 25.0 25.0 25.0 25.0 25.0 16-R67* 25.0 Hardnessmm 23 14.7 13.1 16.1 14.8 n/d 16.2 14.0 20.1 Clarity % T 44 12.7 15.412.0 9.9 1.6% 0.7 23.0 6.1 Example No 3.10 3.11 3.12 3.13 3.14 3.15 3.163.17 3.18 Ingredient % by weight CDP2 1.5 1.7 1.5 1.5 1.7 2.0 CDP10 1.0CDP11 0.7 CDP12 0.4 11-GP1 2.0 4.0 2.0 2.0 4.0 4.0 4.0 18-DBS 0.25 0.419-12-HSA 5.0 1-ISA 17.8 18.46 15.51 15.735 16.14 17.98 15.848 15.91615.32 10-704 53.45 52.48 52.99 53.765 55.16 51.1 54.152 54.384 53.303-BMA 1.96 1.92 1.98 7-TN 14-A418 25.0 25.0 25.0 25.0 25.0 25.0 25.023-PSG 25.0 25.0 Properties Hardness mm 13.5 17.2 13.3 12.1 14.4 14.213.7 14.2 16.9 Clarity % T 19.4 15.3 12.2 2.2 13.2 26.6 27.5 15.0 8.7Clarity- 2 3 0 −9 7 6 4 1 0 visual score

[0149] From Table 8, it can be seen that clear cosmetic sticks areobtainable using various combinations of oils as continuous carrierphase together with the CDP structurants, either alone or with aco-structurant.

Example 4

[0150] Opaque Emulsion Sticks

[0151] In a first step in making opaque emulsion sticks according thepresent invention, a solution of the selected invention structurant, andif present GP1, in ISA was made by the same method as in the process formaking suspension sticks (Example 3). The remaining water immisciblecarrier oils together with an emulsifier, Abil EM 90, were heated to 85°C. in an oil bath whilst being shear mixed at 2500 rpm. The solution ofantiperspirant active was heated to 80° C. and introduced gradually intothe oil/emulsifier mixture, and the resultant mixture was kept constantby heating at 85° C. and sheared at 7500 rpm for 5 minutes. The emulsionwas the mixed into the solution of the structurant solution which hadbeen allowed to cool to ˜90° C. The resultant mixture was stirredbriefly to achieve complete mixing, poured into commercial 50 g stickbarrels at approximately 80° C. and allowed to cool. The formulationsand properties of the sticks are summarised in Table 9 below. TABLE 6Example No 4.1 4.2 Ingredient % by weight CDP1 1.5 CDP2 1.5 1-ISA 29.027.0 7-TN 29.0 27.0 11-GP-1 4 12-EM90 0.5 0.5 15-Z50 40.0 40.0Properties Hardness (mm) 27.8 17.1 pay-off (g) at t_(o) on wool 0.660.80 whiteness t = 24 hr on wool 17 18

[0152] From Table 6, it can be seen that the use of the monohydricalcohol in conjunction with the other water-immiscible oils enables theemulsion formulations to be made quite easily.

Example 5

[0153] Clear Emulsion Stick

[0154] In this Example, the general method of making emulsion sticksdescribed in Example 5 was followed, preceded by a preparatory step forrefractive index matching in order to obtain a translucent emulsionstick.

[0155] In the preparatory step, the refractive indices of theingredients of the organic and aqueous phases in the emulsion wereobtained or measured, and proportions of those ingredients estimated,based on calculation and measurement, such that the two phases hadroughly matched refractive indices. The two phases containing theestimated proportions of ingredients were prepared, their refractiveindices measured and the proportions of the carrier oils in thecontinuous (water-immiscible) phase were adjusted to the extentnecessary to more closely match the RI of the disperse aqueous phase. InExample 5.2, the CDP structurant was fully dissolved in the mixture ofmonohydric alcohols before being mixed with the remainder of the carrieroils and subsequently with the antiperspirant active.

[0156] The Versamid polymer when employed was dissolved simultaneouslywith the cyclic dipeptide structurant. Any silica was incorporated insuspension in a fraction of the water-immiscible oil(s) and anyantiperspirant active supplied as a solid was first dissolved in thespecified weight of water.

[0157] The formulation and its properties are summarised in Table 7below, in which nd indicates that a particular test was not carried out.TABLE 7 Example No 5.1 5.2 5.3 5.4 5.5 Ingredient % by weight CDP2 1.52.0 2.0 1.5 2.0 1-ISA 21.14 12.84 18.51 20.92 43.45 3-BMA 4.61 7-TN 5.718.22 5.05 5.65 8-245 21.14 26.83 20.44 20.93 11.77 12-EM90 0.5 0.5 1.01.0 0.49 15-Z50 40.0 40.0 40.0 40.0 water 16.52 22-36GP 24.77 17-GOH10.0 10.0 10.0 10.0 Fragrance 1.0 Properties Hardness mm 18.6 16.1 13.411.9 17.2 Clarity % T 6.7 1.9 n/d n/d n/d Clarity 1 nd n/d n/d n/d(visual score) Example No 5.6 5.7 5.8 5.9 5.10 Ingredients % by weightCDP2 2.0 2.0 2.0 1.5 1.5 1-ISA 42.66 41.08 43.05 20.6 21.65 7-TN 5.553.95 8-245 11.56 11.14 11.67 20.60 21.65 17-GOH 10.0 10.0 15-Z50 40.040.0 water 17.58 17.78 17.78 22-36GP 23.71 23.71 13-R908 23.71 12-EM900.49 0.49 0.49 0.75 0.75 20-930 1.0 2.0 1.0 1.0 27-H30 0.50 28-H30RX 1.02.0 29-H18 0.5 Properties Hardness (mm) 14.4 19.9 17.2 14.8 14.7 Clarity(% T) 42.0 19.0 58.4 0.82 0.74 Clarity (visual 4 −1 7 n/d n/d score)

[0158] From Table 7 it can be seen not only that clear emulsion stickscan be made that include a faction of a water-miscible liquid, glycerol,but also that it can be made easily employing prior dissolution of thestructurant in the monohydric alcohols.

[0159] Test Methods

[0160] i) Purity of CDP

[0161] The purity of CDP materials Al to A9 was measured by reversephase HPLC with ultraviolet (UV)detection.

[0162] A mobile phase was made comprising 300ml aliquot of deionisedwater, to which was added a 700ml aliquot of HPLC grade acetonitrile and1.0 ml of trifluoroacetic acid (Aldrich spectrophotometric grade, TFA)and mixed thoroughly. 0.00 lg of CDP sample was weighed into a 2 ml HPLCvial and made up to volume with the mobile phase.

[0163] The sample was then analysed in a Hewlett Packard HPLC analyserequipped with a Hypersil ODS 5μm C₁₈, 250×4.6mm @ Room Temp column, aHewlett-Packard 1050 Series Autosampler and Hewlett-Packard 1050 UVDiode Array @ 210nm Detector. The analysis was carried under thefollowing conditions Isocratic/gradient Isocratic Flow rate 1.2ml/minute Run time 5 minutes Temperature Ambient Injection volume 20 μl

[0164] ii) Dissolution Temperature

[0165] The dissolution temperature of the CDP was determined by forminga mixture of the particulate CDP and the selected carrier liquid atambient temperature keeping the particulates in suspension with a mixerbar and raising the temperature of the mixture at a rate that wasinitially faster and later of approximately 2° C. per minute as thedissolution temperature was approached more closely. The dissolutiontemperature was assessed as the temperature at which particulates wereno longer visible.

[0166] iii) Gelling Temperature

[0167] The gelling temperature of a gelled oil phase was determined byfirst preparing a solution of the CDP in the selected oil(s) in glasstubes, having a diameter of 20mm and equipped with a glass thermometerresting on the bottom of the tube, in accordance with the descriptionfor Example 1 herein, and thereafter permitting the resultant solutionin the tubes to cool naturally under quiescent conditions, ie withoutany cooling air being blown over the tubes and without the solutionbeing stirred. External laboratory air temperature was about 23° C.Periodically, the thermometer was lifted by a few mm and if liquid hadnot flowed to fill the void under gravity, was carefully replaced on thetube bottom. The solution was considered to have formed a gel when itdid not flow underneath the thermometer.

[0168] Stick Characterisation—Measurement of Properties

[0169] iv) Stick hardness—Penetrometer

[0170] The hardness and rigidity of a composition which is a firm solidcan be determined by penetrometry. If the composition is a softer solid,this will be observed as a substantial lack of any resistance to thepenetrometer probe.

[0171] A suitable procedure is to utilises a lab plant PNT penetrometerequipped with a Seta wax needle (weight, 2.5 grams) which has a coneangle at the point of the needle specified to be 9°10′±15′. A sample ofthe composition with a flat upper surface is used. The needle is loweredonto the surface of the composition and then a penetration hardnessmeasurement is conducted by allowing the needle with its holder to dropunder a total weight, (i.e. the combined weight of needle and holder) of50 grams for a period of five seconds after which the depth ofpenetration is noted. Desirably the test is carried out at a number ofpoints on each sample and the results are averaged. Utilising a test ofthis nature, an appropriate hardness for use in an open-ended dispensingcontainer is a penetration of less than 30 mm in this test, for examplein a range from 2 to 30 mm. Preferably the penetration is in a rangefrom 5mm to 20 mm.

[0172] In a specific protocol for this test measurements on a stick wereperformed in the stick barrel. The stick was wound up to project fromthe open end of the barrel, and then cut off to leave a flat, uniformsurface. The needle was carefully lowered to the stick surface, and thena penetration hardness measurement was conducted. This process wascarried out at six different points on the stick surface. The hardnessreading quoted is the average value of the 6 measurements.

[0173] v) Deposition by firm sticks (pay-off)

[0174] Another property of a composition is the amount of it which isdelivered onto a surface when the composition is drawn across thatsurface (representing the application of a stick product to human skin),sometimes called the pay-off. To carry out this test of deposition whenthe composition is a firm stick, able to sustain its own shape, a sampleof the composition with standardised shape and size is fitted toapparatus which draws the sample across a test surface understandardised conditions. The amount transferred to the surface isdetermined as an increase in the weight of the substrate to which it isapplied. If desired the colour, opacity or clarity of the deposit maysubsequently be determined. A specific procedure for such tests ofdeposition and whiteness applicable to a firm solid stick used apparatusto apply a deposit from a stick onto a substrate under standardisedconditions and then measures the mean level of white deposits usingimage analysis.

[0175] The substrates used were:

[0176] a: 12×28cm strip of grey abrasive paper (3M™ P800 WetorDry™Carborundum paper)

[0177] b: 12×28cm strip of black Worsted wool fabric.

[0178] The substrates were weighed before use. The sticks werepreviously unused and with domed top surface unaltered.

[0179] The apparatus comprised a flat base to which a flat substrate wasattached by a clip at each end. A pillar having a mounting to receive astandard size stick barrel was mounted on an arm that was moveablehorizontally across the substrate by means of a pneumatic piston.

[0180] Each stick was kept at ambient laboratory temperature overnightbefore the measurement was made. The stick was advanced to project ameasured amount from the barrel. The barrel was then placed in theapparatus and a spring was positioned to biassed the stick against thesubstrate with a standardised force. The apparatus was operated to passthe stick laterally across the substrate eight times. The substrate wascarefully removed from the rig and reweighed. The whiteness of thedeposit could subsequently be measured as described at (v) below.

[0181] vi) Whiteness of Deposit

[0182] The deposits from the at test (ii) above, were assessed for theirwhiteness shortly after application (ie within 30 minutes) or after aninterval of 24 hours approximately.

[0183] This was done using a Sony XC77 monochrome video camera with aCosmicar 16mm focal length lens positioned vertically above a blacktable illuminated from a high angle using fluorescent tubes to removeshadowing. The apparatus was initially calibrated using a referencewhite card, after the fluorescent tubes had been turned on for longenough to give a steady light output. A cloth or Carborundum paper witha deposit thereon from the previous test was placed on the table and thecamera was used to capture an image. An area of the image of the depositwas selected and analysed using a Kontron IBAS™ image analyser. Thisnotionally divided the image into a large array of pixels and measuredthe grey level of each pixel on a scale of 0 (black) to 255 (white). Theaverage of the grey intensity was calculated. This was a measure of thewhiteness of the deposit, with higher numbers indicating a whiterdeposit. It was assumed that low numbers show a clear deposit allowingthe substrate colour to be seen.

[0184] vii) Clarity of formulation—Light transmission

[0185] The translucency of a composition may be measured by placing asample of standardised thickness in the light path of aspectrophotometer and measuring transmittance, as a percentage of lighttransmitted in the absence of the gel.

[0186] This test was carried out using a dual-beam Perkin Elmer Lambda40 spectrophotometer. The sample of composition was poured hot into a4.5 ml cuvette made of poly(methyl-methacrylate) (PMMA) and allowed tocool to an ambient temperature of 20-25° C. Such a cuvette gives a 1 cmthickness of composition. Measurement was carried out at 580 nm, with anidentical but empty cuvette in the reference beam of thespectrophotometer, after the sample in the cuvette had been held for 24hours. A transmittance measured at any temperature in the range from20-25° C. is usually adequately accurate, but measurement is made at 22°C. if more precision is required.

[0187] viii) Clarity of Formulation—Visual assessment score

[0188] A gel contained within a 1 cm thick cuvette was placed directlyon to a sheet of white paper on which 21 sets of figures where printedin black. The size and thickness of the figures varied systematicallyand were numbered from -12 (the largest, thickest set) through 0 to 8(the smallest thinnest set) The score given to each gel was the highestnumbered set which could be read clearly through the gel, the higher thenumber, the higher the clarity.

1. A cosmetic composition comprising: (i) a cosmetic active material(ii) a continuous phase which comprises a monohydric alcohol having amelting point of below 30° C. and a boiling point of greater than 100°C. and optionally at least one water-immiscible liquid carrier oil (iii)a structurant for the continuous phase which comprises a cyclodipeptidehaving the general formula 1

in which at least one of R₁ and R₂ which may be the same or differentrepresents an aliphatic group that is optionally substituted by anaromatic or cycloaliphatic group and the other may alternativelyrepresent hydrogen.
 2. A composition according to claim 1 in which themonohydric alcohol has a melting point of below 20° C. and a boilingpoint of greater than 120° C.
 3. A composition according to claim 2 inwhich the monohydric alcohol is selected from linear or branchedaliphatic alcohols or benzyl alcohol that satisfy such melting andboiling point criteria.
 4. A composition according to claim 3 in whichthe monohydric alcohol is iso-stearyl alcohol and/or benzyl alcohol. 5.A composition according to claim 1 in which the continuous phasecomprises at least 5% by weight monohydric alcohol.
 6. A compositionaccording to claim 5 in which the continuous phase comprises from 20 to80% monohydric alcohol.
 7. A composition according to claim 1 or 6 inwhich one of R₁ and R₂ represents an aliphatic ester group of formula—(CH₂)_(n)—CO₂—R₃ in which n is an integer of at least 1 and R₃represents an alkyl, cycloalkyl or aryl group.
 8. A compositionaccording to claim 1 or 6 in which one of R₁ and R₂ represents a phenylpolymethylene group.
 9. A composition according to claim 8 in which R₁represents —CH₂—Ph.
 10. A composition according to claim 8 in which R₂represents an aliphatic ester of formula —CH₂—CO₂—R₃ and R₃ represents acarbocyclic or heterocyclic group.
 11. A composition according to claim10 in which R₁ represents —CH₂—Ph.
 12. A composition according to claim11 in which R₃ represents a single ring, optionally bridged.
 13. Acomposition according to claim 11 in which R₃ comprises a carbocyclicring substituted by at least one alkyl or alkenyl substituent.
 14. Acomposition according to claim 13 in which the alkyl substituent ismethyl or isopropyl.
 15. A composition according to claim 13 in whichthe ring in R₃ is a cyclohexane or benzene ring substituted by a methyland an isopropyl group that are para to each other.
 16. A compositionaccording to claim 13 in which R₃ is derivable from thymol,isopinocamphenol or a 3,5-dialkyl cyclohexanol.
 17. A compositionaccording to claim 16 in which R₃ is derivable from thymol.
 18. Acomposition according to claim 16 in which the 3,5-dialkyl cyclohexanolis 3,5-dimethyl cyclohexanol.
 19. A composition according to claim 1 inwhich the cyclo dipeptide is present at a concentration of from 0.1 to15% by weight of the composition.
 20. A composition according to claim20 in which the cyclodipeptide compound is present at a concentration offrom 0.3 to 10% by weight of the composition.
 21. A compositionaccording to claim 20 in which the cyclodipeptide compound is present ata concentration of from 0.5 to 5% by weight of the composition.
 22. Acomposition according to claim 19 in which the cyclodipeptide compoundis present at a concentration of from 0.4 to 8% by weight of thecontinuous phase.
 23. A composition according to claim 1 in which thewater-immiscible oil comprises a silicone oil and/or a non-siliconehydrophobic organic liquid selected from hydrocarbons, hydrophobicaliphatic esters, aromatic esters and hydrophobic ethers.
 24. Acomposition according to claim 1 wherein the water-immiscible carrierliquid contains silicone oil in an amount which is at least 10% byweight of the composition.
 25. A composition according to claim 1 whichcontains not more than 3% by weight of any fatty alcohol which is solidat 20° C.
 26. A composition according to claim 1 in which the cyclodipeptide is employed in conjunction with a further structurantcomprising an N-acyl amino acid derivative.
 27. A composition accordingto claim 26 in which the further structurant is N-lauroyl glutamic aciddibutylamide.
 28. A composition according to claim 1 in which12-hydroxystearic acid is employed as a further structurant.
 29. Acomposition according to claim 1 in which a polyamide is employed as afurther structurant.
 30. A composition according to claim 26, 27, 28 or29 in which the further structurant is employed in a weight ratio to thecyclo dipeptide of from 1:10 to 10:1.
 31. A composition according toclaim 1 in which a further structurant comprising a dibenzylidenealditol is employed.
 32. A composition according to claim 31 in whichdibenzilidene sorbitol is employed at a weight ratio to thecyclodipeptide structurant of from 1:3 to 1:10.
 33. A compositionaccording to claim 1 in which the composition comprises a suspension ofthe cosmetic active in the structured hydrophylic carrier liquid.
 34. Acomposition according to claim 33 in which the carrier liquid and thesuspended cosmetic active have matched refractive indices and has alight transmission of at least 1%.
 35. A composition according to claim1 wherein the composition is an emulsion with the cosmetic active insolution in a hydrophilic, preferably water-miscible, disperse phase.36. A composition according to claim 35 wherein the disperse phasecontains a diol or polyol.
 37. A composition according to claim 36wherein the disperse phase contains glycerol or 1,2-propane diol.
 38. Acomposition according to claim 35 in which the composition contains from0.1% to 10% by weight of a nonionic emulsifier.
 39. A compositionaccording to claim 38 in which the emulsifier is an alkyl dimethiconecopolyol.
 40. A composition according to claim 35 in which therefractive indices of the disperse and continuous phases of the emulsionare matched.
 41. A cosmetic composition according to claim 1 in whichthe cosmetic active is an antiperspirant or deodorant active.
 42. Acomposition according to claim 41 in which the antiperspirant activecomprises an aluminium and/or zirconium halohydrate, an activatedaluminium and/or zirconium halohydrate, or an aluminium and/or zirconiumcomplex or an activated aluminium and/or zirconium complex.
 43. Acomposition according to claim 41 in which the complex contains bothaluminium and zirconium.
 44. A composition according to claim 41 whichcontains from 5 to 40% by weight of the antiperspirant active.
 45. Ancosmetic product comprising a dispensing container having an aperturefor delivery of a stick, means for urging the contents of the containerto the said aperture or apertures, and a composition according to claim1 accommodated within the container.
 46. A product according to claim 45wherein the composition is a firm gel such that a penetrometer needlewith a cone angle of 9 degrees 10 minutes, drops into the gel for nomore than 30 mm when allowed to drop under a total weight of 50 gramsfor 5 seconds.
 47. A process for the production of a compositionaccording to claim 1 comprising the steps of: a) forming a mixturecontaining a liquid carrier, a structurant dissolved therein, and asolid or a disperse liquid phase comprising cosmetic active inparticulate or dissolved form at a temperature of at least 40° C. and isabove the setting temperature of the mixture; b) introducing the mixtureinto a mould which preferably is a dispensing container, and c) coolingor permitting the mixture to cool to ambient temperature, in which thestructurant is a cyclo dipeptide that satisfies the general formula 1:

in which at least one of R₁ and R₂ which may be the same or differentrepresents an aliphatic group that is optionally substituted by anaromatic or cycloaliphatic group and the other may alternativelyrepresent hydrogen, and the carrier comprises a monohydric alcoholhaving a melting point of below 30° C. and a boiling point of greaterthan 100° C., and optionally at least one water-immiscible liquidcarrier oil.
 48. A process according to claim 47 in which the carriercomprises at least one water-immiscible liquid carrier oil and at least5% monohydric alcohol.
 49. A process according to claim 48 in which thecarrier comprises from 20 to 80% by weight monohydric alcohol.
 50. Aprocess according to any of claims 47 in which the water-immiscibleliquid carrier comprises a silicone oil and/or an aromatic ester.
 51. Aprocess according to claim 47 in which the cyclo dipeptide structurantis dissolved in the monohydric alcohol and up to half of thewater-immiscible oil prior to being mixed with the water-immiscible oilor a residual fraction thereof.
 52. A process according to claim 47which includes a step of pouring the mixture at elevated temperatureinto a dispensing container and allowing it to cool therein so as toproduce a product according to claim
 41. 53. A cosmetic method forpreventing or reducing perspiration on human skin comprising topicallyapplying to the skin a composition according to claim 1.